Hmmm and it’s easy enough to change a CK to GXP retrospectively?

Adapter. Should work for CK BB.

Not sure if it has been mentioned already but the Rotor InPower looks like a nice PM solution. If it comes down to EU Stages pricing (£400-450) then I can see it doing well. It is a shame that the splines aren’t the same as RF Next Sl/ Cannondale Hollowgram then you could have been on to a nice light PM!

Doesn’t fit Treks either! 🙁

after 4 weeks riding the new wheel, the calibration number started dropping. It was always well within the 512 +/- 12 for those first few weeks until sundays ride where it was 480. Recalibrated several times mid ride and it dropped into the 470’s and then the 460’s

also on a g3 – 1st one drifted out to 700+

went back to Paligap, got it back a month ago, bikes been in for other repairs, 535 last night, 536 this morning

Where can you pick up stages for £400?

And agree a BB based power meter, using conventional batteries is a great move – I’ve always thought that the hollow space in the crank spindle could house something useful.

Ergomo did it years and years ago, they had the potential for it to be the first really affordable power meter, but they backed ISIS, just when external bearings had appeared, and they were shit.

Such a shame you’re stuck to Rotor chain rings on the Rex inPower meter, they’re so bloody expensive. I’m stupidly going to ask for a price when I pop into the shop on Sat…

I’m kinda liking oval rings though and this apparently works with ’em, will be waiting for a full DC Rainmaker review!

What’s people’s thoughts for left only on the MTB? I reckon it’d irritate the **** out of me on he road but less so off as it’s less steady efforts so outright accuracy doesn’t really matter?

Left only works for me on my MTB but my left right imbalance has me weaker on the left so data doesn’t give me false highs.

False highs (or lows) are a bit of a non issue as long as they’re consistent, and you’re not using other power meters. May marginally decrease your willy waving prowess with friends, but that’s about it.

Where single sided power meters fall down is if (like monkeyfudger) your balance shifts either as you increase your power and/or as you get tired, or if you’re swapping between power meters which measure differently.

I would have thought it would be worse on the mountain bike. You often pedal sections with power on one foot deliberately due to clear trail obstacles.
I don’t know why it’ll irritate you on the road bike. I think people over worry about it to be honest. If you are consistently producing 40% less power with your left leg then what’s the problem?
Power jumps all over the place when you’re riding anyway, so you are generally looking at an average over a space of time anyway.

If you are consistently producing 40% less power with your left leg then what’s the problem?

That’s what I said, the issue is that a lot of people aren’t like that. They’re 50/50 when spinning along, which changes to 47/53 at threshold, but 45/55 at max.

If you have a Stages on your training bike, so you know you can do 300w for an hour, then great. Until you get on your Quarq equipped TT bike, and pace yourself to 300w, except you now need to do nearly 340w at threshold to maintain that same pace as you do on your Stages, because it’s suddenly brining in your dominant RH power.

Over simplification, but that’s the issue.

Where single sided power meters fall down is if (like monkeyfudger) your balance shifts either as you increase your power and/or as you get tired, or if you’re swapping between power meters which measure differently.

Vector S is pretty good for this as you can set a scale factor. I set it up on the turbo with my PowerTap and did a 2.5 hr ride with sections of powers from about 50 to 200% FTP. Plotted the vector against the PT. Found it to be a pretty consistently about 5% lower. Not much variation across the range. So set the scale factor to 1.045 using the Garmin app, now gives values that pretty much track the PT.

I’d assume you can do the same with all LHS PM?

That’s quite neat, and takes care of the second part of my point, but can’t deal with the disparity changing depending on how knackered you are or how hard you’re pushing.

It’s interesting to see the DCR reckons single sided power meters are going to be a very short term thing, I’m inclined to agree if prices keep falling as they are.

That’s quite neat, and takes care of the second part of my point, but can’t deal with the disparity changing depending on how knackered you are or how hard you’re pushing

Think some do, some don’t. Mine didn’t seem to vary much over the course of a fairly long and hard turbo session. Feels about right out on the road now.

(My P2M estimates about the same imbalance, and that stayed consistent for the duration of a 10 mile TT the other day where I was pedalling some horrendous squares towards the end.)

Good thing about the vectors is that if it does end up bothering you, you always have the option of doubling up and getting the RHS. Can’t do that with a Stages or a Rotor.

I keep prevaricating and just cant click buy yet. Was set for Vectors, but i use SPD-SL so changing pedal system is going to add extra expense – either changing pedals on my other bikes or getting a new pair of shoes (actually 2 pairs as i like to have a a spare pair for use when the other is wet) which adds to the expense. Power2max not really an option as i want to stick to my current crankset. Pioneer looks good and it now seems like a reasonable price but going to be a hassle as they dont have UK stockists.

Then there is Stages due to all the reliability issues i read about i was right off…however saw the Ultegra version for about £500 and its tempting me to take a risk at that price.

But then the main thing holding me back on that is the possibility of a Shimano one sometime soon.

That’s quite neat, and takes care of the second part of my point, but can’t deal with the disparity changing depending on how knackered you are or how hard you’re pushing.

But again, it is a constant that gives numbers to “train” to. I’m still not convinced that the left right balance changes massively even under these conditions but nevertheless any PM is a tool to try and help you get fitter and faster more efficiently than without one and the Stages does that job for me. I’m not too bothered if my 271W FTP is real or not and at the end of the day we are all just Freds pursuing a hobby 😀 The guys finishing at the back of Paris-Roubaix held that power for 6 hours so there’s no point getting delusional about “the numbers” 😀

Where can you pick up stages for £400?

Powermeter24, Stages SRAM X9, £420 to be exact when they had an extra 10 or 20% off across all PM’s. They are £489 at the moment but it is worth keeping an eye the EUR exchange rate. The DS crank is cheap to pick up on ebay as people often swap them out for fancier cranks on new bikes. Think I paid less that £50 so it was around £470 all in.

Then there is Stages due to all the reliability issues

No issues with mine. They have updated firmware, o-rings and the battery covers which I think has helped with the battery life and unit life. People still seem to buy Powertaps for some reason but most people here seem to spend most of their time trying to get them working properly!

Can you not just change cleats on your existing shoes?

I’d not hold my breath for Shimano. At least a couple of years away IMO. Reckon it’ll be at least a year or two after seeing the usual pro spy shots, and there’s no sign of those yet. Shimano are not ones to rush things!

DanW, I think it’s more an issue of comparing against other PM you have and making sure the data is reasonably consistent.

I’m not too bothered if my 271W FTP is real or not and at the end of the day we are all just Freds pursuing a hobby

We’re flitting between the two points I made now! That’s relevant if you’re using the same power meter all the time. Seeing as they’re marketed (and used extensively) as a pacing tool, if you have a different system between bikes that has the potential to be an issue.

See my point about willy waving – that false highs or lows aren’t really relevant as you say – it’s a number, and is repeatable. As long as you don’t change system!

LH is more than adequate for virtually everyone I’m sure, but there are limitations. That’s all I’m saying. For me, given where the market is I’d not buy a LH system right now.

No that’s fair enough. Having said that, if I had multiple bikes I’d want the same system on all bikes. There seems to be enough difference in the absolute values to give enough error in trying to transfer numbers from one PM to the next. If anything, this is even more reason to go for Stages style PM as it is cheaper to kit out multiple bikes but that is just my perspective. I don’t think there is such a thing as a “best” PM, even with an unlimited budget, and we are lucky to have such choice 😀

I’d not hold my breath for Shimano. At least a couple of years away IMO. Reckon it’ll be at least a year or two after seeing the usual pro spy shots, and there’s no sign of those yet.

Pay attention!

They filed patents in 2012, updated them in 2014 and the spy shots are here http://lavamagazine.com/new-shimano-power-meter-spotted-in-the-wild/?cbg_tz=420

My guess would be, a power meter on the next itteration of DA (assuming the usualy 4 years, that means it won’t be in the shops till Autumn 2016) with all the bells and whistles they patented (even upto where on the pedal you apply the pressure to help tweak cleat alignment). Then Ultegra to get a 2 sided stages type system, and then 105 to get a one sided stages type system over the next 3 years as they get re-vamped. Either that or a simple system on DA and we have to wait 4+ years like Di2 for the next itteration with all the features. But given the way the market’s taken off for PM’s I can’t see it being a good idea to drip feed it in that way.

Shimano have a pretty funky static bike PM setup so I wouldn’t have thought they are far off if they indeed do want to bring one to market. On the other hand I wonder if they are happier sticking to what is more comfortable- i.e. a large, bulky but innovative static bike set up rather than the normal PM’s??? You never can tell with Shimano!

Yes saw that, I really meant pro peloton spy shots.

Agree with your timescales for DA. Though reckon it’ll be longer, if ever, before we see any trickle down. Shimano seem happy to take their time over these things.

I don’t know why it’ll irritate you on the road bike

Because I’m mental! Na, but really, I do use it as a pacing tool on the road bike. I don’t think it’d get used half as much for that on an XC bike.

Good points all, food for thought.

LH is more than adequate for virtually everyone I’m sure, but there are limitations. That’s all I’m saying. For me, given where the market is I’d not buy a LH system right now.

This got me thinking, if you were to buy a PM right now which would it be?

Tough choice with the market the way it is. I’d probably go for another P2M, considering price, reliability, being spider based, and best fit for what I need. Though would have a good look at the Quark. Though if it was going to be my first and only PM, I’d probably go vector S, mostly due to price, easy to swap, and upgradable with a second pedal later if I felt the need (already on Keo pedals so that’s not an issue.)

This got me thinking, if you were to buy a PM right now which would it be?

And therein the reason I’ve not replaced my PowerTap! I think LH only wont last. Prices will drop on dual sided. Vector is top of the pile for me at the moment.

Stages is too expensive for my liking given the issues a lot of people are having with reliability and its proximity to dual sided ones. With US pricing it’s a far more viable option

If it was me buying my first for a road bike I’d go P2M again, proper crank based power meter, reliable with user changeable battery and chainrings. Where it falls down for me is wanting one on my XC bike just because I want one, this means I’m not quite prepared to pay full whack so keep looking at the cheaper option, inPower one peaked my interest because it’s inside the axle, I think there’d always be a niggle there for me about cracking a PM on a rock.

I’m kinda hoping we see P2M prices fall, I think they might have to?

I wonder how much this has hurt SRM, are people buying them now because they’re now below a £1000, has the new prices just created new customers and everyone who would have used SRM uses ’em anyway?

Think it’s a case of lower pricing opening up a wider market.

If money were no object I’d go Quark XX1.

My current system is 1x Stages XTR between 3 bikes. Doddle to change. Left sided only is fine for XC and training and it’s the only system I use.

Reliability is down to battery life which seems dampness related. Updated firmware, new door and seal with gasket grease but still ate a battery in a week. I no longer wrap it in tape which was holding damp in once broached and I now carry a spare battery for training and change before races. I spoke to Saddleback unofficialy at BOB who also reckoned battery was down to damp ingress.

It’s such a pity that such a neat tool is compromised.

Had 3 Stages since October and all had issues with the battery draining. Returned it for a refund and I’ve went for a Quarq Riken. Hopefully that will be more reliable.

Here’s another claiming breakthrough pricing that just popped up in my Twitter feed. Not sure I’m convinced about the impact on Q factor. Crowdfunding from Monday.

http://www.cyclingweekly.co.uk/news/latest-news/british-inventor-creates-revolutionary-affordable-power-meter-167250

https://www.facebook.com/Limitspowermeter

http://limits.technology/

Interesting… On paper it sounds great. As you say, the q-factor increase looks substantial.

They have some wibble in the FAQs about test riders finding the wider stance better due to better knee tracking. Smelt a bit like marketing to me.

May go and compare my road bikes with MTBs – I know they’re wider, would be interesting to see how much. But the picture looked like an easy extra 20mm, I’d be surprised if I find that much difference.

Nice idea, be interesting to see what makes it to production. Though even having my cleats a couple of mm out on the road bike gives me knee and ankle bother so I’d be a bit worried about any change in pedal position. I guess there’s no way of making it any narrower than the length of the pedal thread.

Up on Indiegogo now

https://www.indiegogo.com/projects/limits-the-world-s-smartest-cycling-power-meter

Hmmm, can’t decide on that. Not something I want to be an early backer on!

190 dollars, it is quite tempting to take a punt. December 2015 apparently, though given the track record of these sorts of things I’d not expect to see anything till at least mid 2016!

Presumably it’s a pair? Otherwise it really will screw up your q-factor.

Presumably it’s a pair? Otherwise it really will screw up your q-factor.

Left side only. Right will come later, apparently..

Oh yes. So it increases the q-factor on your LH crank? That sounds really desirable 😕

Definitely an interesting theory.